U.N. Secretary General Ban Ki-moon has called for Zimbabwe's unity government to free all political prisoners and fully implement last year's power sharing agreement. The U.N. official spoke in South Africa, at the beginning of a five-nation trip to Africa.  

U.N. Secretary-General Ban Ki-moon welcomed the recent inauguration of Zimbabwe's government of national unity. And he said the United Nations is ready to help Zimbabwe address the enormous challenges afflicting its people.

"That said, I remain concerned about reports of arrests and detention of opposition activists and human rights defenders,"  Ban said.  "I hope that these people will be released as soon as possible."

A power-sharing agreement signed last year created Zimbabwe's unity government.  It brought long-time opposition leader Morgan Tsvangirai into government as prime minister, while President Robert Mugabe remained as head-of-state.

Under the agreement, all political prisoners were to be released.  But about 30 human rights activists and supporters of Mr. Tsvangirai remain in jail.  Some have been detained for months without legal counsel or medical attention.

Mr. Ban noted that a senior U.N. team is currently in Zimbabwe to assess the country's needs.

"The international community, led by the United Nations, stands ready to provide the necessary humanitarian assistance and provide all necessary medical and sanitation support to the Zimbabwean people," he said.  "But all these efforts would get stronger and more support from the international community if we can see the progress in political and national reconciliation."

The U.N. Secretary-General met with South African President Kgalema Motlanthe, who said the Zimbabwean leaders had assured him the release of political prisoners was high on their agenda.

Mr. Ban leaves Thursday for Democratic Republic of Congo and Rwanda, where the United Nations is working to reduce cross-border tensions and ease the plight of one-quarter-million people displaced by recent violence in eastern Congo.

He praised the recent warming of relations between the two governments that has reduced hostilities in the Kivu region and led to a joint military campaign to remove former Rwandan militias from the region.

Mr. Ban also noted that the International Criminal Court next week is to decide whether to issue an arrest warrant against Sudanese President Omar al-Bashir on charges of genocide in the Darfur region.

The African Union strongly opposes such a move.  Mr. Ban said that regardless of the decision, he hoped the Sudanese president would act responsibly and address the issue of peace and security in the region.